> Moreover, having thought a bit more about the "power manager in user space"> concept I'm not sure if it really is that better than the original wakelocks> idea. Namely, it only repaces a kernel-based mechanism with a user space> task doing basically the same thing, but the communication between that task> and the other cooperating user space tasks is arguably more complicated (it> also uses the kernel resources, although indirectly).

That is all true. The "power manager in userspace" was meant to provea point: that this _could_ be done without invasive changes to thekernel. It wasn't necessarily meant to be a _better_ solution.

> So, for a phone-like system, where you'd generally want to simplify user space,> having a "power manager" in the kernel seems to make sense to me.

This is a judgment call. Obviously different people have different opinions.